package org.apache.maven.model.profile.activation;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.maven.model.Activation;
import org.apache.maven.model.Profile;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.building.ModelProblem.Severity;
import org.apache.maven.model.building.ModelProblem.Version;
import org.apache.maven.model.building.ModelProblemCollectorRequest;
import org.apache.maven.model.profile.ProfileActivationContext;
import org.codehaus.plexus.component.annotations.Component;

/**
 * Determines profile activation based on the version of the current Java runtime.
 * 
 * @author Benjamin Bentmann
 * @see Activation#getJdk()
 */
@Component(role = ProfileActivator.class,
    hint = "jdk-version")
public class JdkVersionProfileActivator implements ProfileActivator {

  public boolean isActive(Profile profile, ProfileActivationContext context, ModelProblemCollector problems) {
    Activation activation = profile.getActivation();

    if (activation == null) {
      return false;
    }

    String jdk = activation.getJdk();

    if (jdk == null) {
      return false;
    }

    String version = context.getSystemProperties().get("java.version");

    if (version == null || version.length() <= 0) {
      problems.add(new ModelProblemCollectorRequest(Severity.ERROR, Version.BASE)
          .setMessage("Failed to determine Java version for profile " + profile.getId())
          .setLocation(activation.getLocation("jdk")));
      return false;
    }

    if (jdk.startsWith("!")) {
      return !version.startsWith(jdk.substring(1));
    } else if (isRange(jdk)) {
      return isInRange(version, getRange(jdk));
    } else {
      return version.startsWith(jdk);
    }
  }

  private static boolean isInRange(String value, List<RangeValue> range) {
    int leftRelation = getRelationOrder(value, range.get(0), true);

    if (leftRelation == 0) {
      return true;
    }

    if (leftRelation < 0) {
      return false;
    }

    return getRelationOrder(value, range.get(1), false) <= 0;
  }

  private static int getRelationOrder(String value, RangeValue rangeValue, boolean isLeft) {
    if (rangeValue.value.length() <= 0) {
      return isLeft ? 1 : -1;
    }

    value = value.replaceAll("[^0-9\\.\\-\\_]", "");

    List<String> valueTokens = new ArrayList<String>(Arrays.asList(value.split("[\\.\\-\\_]")));
    List<String> rangeValueTokens = new ArrayList<String>(Arrays.asList(rangeValue.value.split("\\.")));

    addZeroTokens(valueTokens, 3);
    addZeroTokens(rangeValueTokens, 3);

    for (int i = 0; i < 3; i++) {
      int x = Integer.parseInt(valueTokens.get(i));
      int y = Integer.parseInt(rangeValueTokens.get(i));
      if (x < y) {
        return -1;
      } else if (x > y) {
        return 1;
      }
    }
    if (!rangeValue.closed) {
      return isLeft ? -1 : 1;
    }
    return 0;
  }

  private static void addZeroTokens(List<String> tokens, int max) {
    while (tokens.size() < max) {
      tokens.add("0");
    }
  }

  private static boolean isRange(String value) {
    return value.startsWith("[") || value.startsWith("(");
  }

  private static List<RangeValue> getRange(String range) {
    List<RangeValue> ranges = new ArrayList<RangeValue>();

    for (String token : range.split(",")) {
      if (token.startsWith("[")) {
        ranges.add(new RangeValue(token.replace("[", ""), true));
      } else if (token.startsWith("(")) {
        ranges.add(new RangeValue(token.replace("(", ""), false));
      } else if (token.endsWith("]")) {
        ranges.add(new RangeValue(token.replace("]", ""), true));
      } else if (token.endsWith(")")) {
        ranges.add(new RangeValue(token.replace(")", ""), false));
      } else if (token.length() <= 0) {
        ranges.add(new RangeValue("", false));
      }
    }
    if (ranges.size() < 2) {
      ranges.add(new RangeValue("99999999", false));
    }
    return ranges;
  }

  private static class RangeValue {
    private String value;

    private boolean closed;

    RangeValue(String value, boolean closed) {
      this.value = value.trim();
      this.closed = closed;
    }

    public String toString() {
      return value;
    }
  }

}
